Intraluminal occlusion devices are used to block fluid flow through bodily passages. In certain clinical situations, such as surgical procedures during which a bloodless field is desired, a temporary blockage of fluid flow is desired. In other situations, a permanent blockage of fluid flow is desired.
The art contains a variety of occlusion devices that perform the occlusion function with various degrees of efficiency and effectiveness. Several of these devices, however, have drawbacks that limit their usability. For example, some occlusion devices, such as the Amplatzer Septal Occluder (AGA Medical Corporation, Plymouth, Minn.), contain complex, multi-filament frame structures that contribute significant bulk to the overall profile of the occlusion device, effectively limiting its use to only relatively large bodily passages that can accommodate the bulk of the device and the catheter used to deliver and deploy the device. Also, many occlusion devices rely on thrombosis—the formation of a thrombus at the site of deployment of the occlusion device—as the mechanism for occlusion. While such devices may provide the desired blockage once a thrombus forms, the thrombus can be partially reabsorbed over time, which may reduce the effectiveness of these occlusion devices as the embolized bodily passage becomes recanalized and fluid flow is restored. Furthermore, because of their reliance on thrombus formation to achieve occlusion, these devices may have limited effectiveness in patients with a reduced ability to form blood clots, such as patients undergoing anti-coagulant therapy and/or thrombolytic therapy with tissue plasminogen activator (tPA), streptokinase, or a similar agent.
Occlusion of relatively large body vessels presents additional challenges for which prior art devices have proven insufficient. For example, occlusion devices with insufficient radial strength for maintaining a seal against a wall of a larger vessel can result in leakage around the perimeter of the occlusion device. Furthermore, with insufficient radial strength, the occlusion device can tilt or shift within the vessel over time, further impacting its ability to block fluid flow.
Accordingly, a need exists for improved occlusion devices for blocking fluid flow through bodily passages.